摘要
2004年9月5日上午11时25分,重庆万州区铁峰乡吉安村发生一大型滑坡--民国场滑坡.该滑坡呈长扇形展布,前缘宽约550m,后缘宽约100m,纵长约1350m,前缘与后缘高差约325m;平均厚度约10m,面积为5.4×105m2,体积为5.4×106m3.此滑坡为顺层基岩滑歧;滑动面为炭质页岩,平直、光滑;总滑动方向呈NW 325°,滑动方式为牵引式.滑坡堆积物以块石、粘土及被毁建筑物碎屑为主.在滑坡的前部最厚可达35m,一般20～25m;中部陡坡地段厚度小于5m,缓坡地段厚度一般15～20m.后部分布最薄,仅1～2m,部分地段出露滑面(滑床).滑坡形成机制:顺坡向、中等倾角的地质结构及岩层中的炭质页岩是其形成的内在条件;河流冲刷与人类活动是形成的外部动力;暴雨是导致滑坡发生的直接诱发因素.民国场滑坡的发生警示:在三峡水库区Ⅲ期地质灾害勘察、设计及治理中必须对万州区顺坡向、中缓倾角且具有软弱夹层的库岸斜坡充分重视.
Mingguochang Landslide took place in Jian Village, Tiefeng Town, Wanzhou district, at 11：25 am September 5, 2004. The landslide with 550m in foot width, 100m in head width, 1300m in length, 10m in average thickness,5.4×10^5m^2 in area and 5.4×10^6 m^3 in volume, slipped along a carbonaceous shale stratum surface which is very smooth, and the slip direction is about 325°. The thickness of the displaced material is about 20-30m at the lower part of the landslide, about 15-20m at the fiat place in the middle part of the landslide, less than 5m at the steeper place in the middle part of the landslide, and 0-2m at the upper part of the landslide. The displaced material is composed of disintegrated stone, clay and destroyed building material, etc. The formation mechanism of the landslide may be described as follows ： （1） The geological structures,i.e, the dip direction of strata is in the same direction as that of the slope, and the slope-forming material is carbonaceous shale, are the geological dominant factors to cause the landslide. （2）The erosion of Yangjia River and the activity of human being are considered important external causes of the landslide. （3）Rainstorm is the triggering factor to the landslide. The occurring of Minguochang Landslide gives important warning to people that great attention should be paid to the investigation, reconnaissance, and control of the bank slopes in Wanzhou District for where the geological structures are similar to Minguochang slope tor the 3^et geodisaster prevention in the Three Gorge researvoir.
出处
《中国地质灾害与防治学报》
CSCD
2005年第4期20-23,共4页
The Chinese Journal of Geological Hazard and Control
关键词
万州区铁峰乡
民国场滑坡
特征
形成机制
暴雨
Tiefeng Town of Wanzhou District
Minguochang landslide
characteristics
formation mechanism
rainstorm
